Not applicable.
Not applicable.
The present invention relates to an apparatus for dividing or subdividing stacks of narrow items, such as mail pieces, which are standing on a base and leaning against a supporting wall.
The division of bigger stacks into subdivisions of any size, where the shape of the stack is maintained, permits automatic further processing of the stack sections. Oftentimes, the stack division is performed manually with a swiveling or rotating in of one or more separation knives.
Known automatic means may also be employed. One such means occurs where the lower edge of a compact stack of mail pieces is spread by producing a gap, with different speeds, at defined places, by conveying belts. Then several teeth of a rake type apparatus emerge from below, enter the stack of mail pieces, and extend vertically upwards. A problem exists with this method, namely, with the immersion of several teeth arranged in a row supporting large-surface mail pieces, one or more mail pieces can get caught between the teeth, so that these mail piece(s) get jammed. The mail pieces can therefore not be allocated to a select stack division and often lead to a jam. The cause for this lies mostly with mail pieces which were sorted one-sided and/or mail pieces which are not parallel to the teeth. Furthermore, the teeth can move the mail pieces out of their aligned position, which causes problems during subsequent processing. Accordingly, a need exists to address the above discussed difficulties.
The present invention is generally directed to an apparatus for the division of stacks. The stacks may comprise relatively narrow mail pieces which stand upright and lean against a supporting wall, where obstructions, due to mail piece jams and/or dislocations, are reduced in comparison with the current state of the art. The application, according to the invention, of only one circularly bent supporting finger directed towards the supporting wall (the finger movable upwards through an opening in the base) prevents a jamming of unevenly placed mail pieces. Via the bend towards the supporting wall and during the run-up of the supporting finger, an orientation or urging of the engaged mail pieces also occurs in cooperatively with the friction force component of the supporting wall. The bent supporting finger may comprise a plurality of interlaced fingers. The direction of their bend or arc may be towards and/or away from the supporting wall.
If the bend radius and the length of the circular arc segment are chosen in such a way that the end of the supporting finger exhibits a component of motion directed at the base at the moment of the impact on the supporting wall, then the touched mail pieces are additionally orientated towards the base by the respective friction force component. A possible run-up of the touched mail pieces can thereby be compensated at the beginning of the extending motion of the supporting finger. Accordingly, it is advantageous to effect the bend radius of the supporting finger to be smaller than the height of the smallest mail piece.
If the mail pieces of the stack comprise substantially different sizes, i.e. if for example mail pieces double in size need to be supported, it is advantageous to push upwards an additional circularly bent or arcing supporting finger through the opening in the base. It is advantageous to only push upwards the additional supporting fingers when the first supporting finger is completely extended and the mail pieces which were touched by it are fixed. A dislocation of the mail pieces during the run-up of the additional supporting fingers is thereby prevented. The bend radius of the additional supporting fingers is advantageously greater than or equal to the height of the biggest mail piece. The bending or urging of the additional supporting fingers can thereby be directed towards the supporting wall as well as away from it, so that the large mail pieces are safely supported over their entire surface.
To keep the opening in the base as small as possible, the supporting finger for the smallest mail piece and optionally the additional supporting fingers comprise open hollow sections or grooves so as to accommodate or interlace other supporting fingers therein.
For a realization of finger urging, each bent supporting finger is advantageously and connected to a rotary arm arranged below the base. The arm pivots about a point such that an upward motion of the arm portion connected the supporting finger imparts upward force on the particular finger, thereby urging it through the opening. The arm or rotary arm may swivel by a controlled rotary drive. In an additional advantageous embodiment of actuation, the supporting fingers are piloted and driven in a bent guide piece. The actuation can be realized in a way and manner known in the art, for example by wheel and disk drive, rack gear, linear motor, and the like.
The above and other advantages are facilitated by an apparatus for dividing a stack of items resting on a base and standing upright against a supporting wall, comprising: walls within said base defining an opening; at least one supporting finger for dividing said stack, said at least one finger having an arc shape in a direction of said supporting wall and positioned within said opening; a drive mechanism functionally associated with said at least one finger so as to urge said at least one finger through said opening and engage said stack; and a distance between said opening and supporting wall set so as not to be greater than a length of a smallest item in said stack.
It is also advantageous to implement the supporting fingers so that they converge narrow towards their ends. Accordingly, it is now possible to do away with additional means for the spreading of the stack before the use of the supporting fingers. Other features and advantages of the present invention will become evident from the specification and claims below.